I'm searching same open source software to perform this kind of limit (without restricting and executing the limit to a variable):
$$ \lim_{(x, y)\to(0, 0)}\frac{x^3y}{x^6+y^2} $$ I've seen sage and maxima, but i don't know if they can help me... Then, if not this, can they perform double and triple integrals?
The limit does not exist since:
$\textbf{Case 1:}$ Let $(x,y) = (x, x^3)$ then we have: $$\lim_{(x, y)\to(0, 0)}\frac{x^3y}{x^6+y^2}=\lim_{(x, x^3)\to(0, 0)}\frac{x^6}{x^6+x^6}=\frac{1}{2}$$ $\textbf{Case 2:}$ Let $(x,y) = (x, 0)$ then we have: $$\lim_{(x, y)\to(0, 0)}\frac{x^3y}{x^6+y^2}=\lim_{(x, 0)\to(0, 0)}\frac{x^3 \cdot 0}{x^6}=0$$